Warrant and Proper Function.

'Reformed Epistemology', and associated expressions such as 'strong foundationalism', 'proper basicality' and 'the Great Pumpkin objection' have in recent years become part of the stock in trade of epistemology. Alvin Plantinga, Nicholas Wolterstorff, George Mavrodes and others have pioneered a critique of strong foundationalism, a foundationalism needing indubitable or self-certifying foundational propositions, in favour of a weak foundationalism which permits, for example, theistic propositions to be among the foundations of a person's noetic structure.

These views, fostered by a series of papers from these authors, and especially those to be found in Faith and Rationality edited by Plantinga and Wolterstorff, were formulated in terms of particular version of internalism in epistemic justification, that which stressed (in a way made famous by W. K. Clifford, though by no means original to him) epistemic obligation and permission.

These two impressive volumes, the first two a trilogy, mark a shift away from this earlier internalism by the leading practitioner of 'Reformed epistemology', and a radical new strategy. Indeed the first volume contains a sustained critique of internalism, and of some varieties of reliabilism, while the second volume contains a detailed though incomplete defence of version of externalism, a naturalised epistemology requiring a supernatural metaphysic, a position to be discussed and defended in the promised third volume of the trilogy. Not only is the scale of the work more ambitious than the earlier papers, but the doctrine is as well. For Plantinga now wishes to argue not that it is permissible for a person to have the proposition God exists in the foundations of his noetic structure, but rather that no account of knowledge can be provided that is not externalist. And though such externalism might appear naturalistic, and indeed up to a point is, the most persuasive grounding of such externalism is to be found in a …